Planar slides and cards are used to perform diagnostic tests, including blood, urine and sputum chemistry tests as well as blood typing. Similar layered devices containing immobile nutrient components are used for culturing microorganisms. The cards and slides commonly contain a protective cover to protect and preserve the specimen or culture media during incubation or for storage purposes.
U.S. Pat. No. 3,990,850 describes a test card, which includes a substrate that has a test surface which is substantially insoluble in, impermeable to, non-absorbent to and wettable by water and carrying a dried test reagent. An er'd flap folds over the test area to enclose and preserve the specimen in a blood typing test. The card has a spot of blood typing anti-serum to which the blood sample is added. The flap has bonded thereon an absorbent blotting paper around the test area. The results may be viewed through a transparent plastic opening or window in the now folded flap.
U.S. Pat. No. 3,996,006 shows a test sheet which includes a sheet underlying openings in the front panel. Reagents are added to the paper sheet. The sheet may be divided into test sections. The '850 and '006 test slides are described as useful for immunological tests.
The manufacture of these devices, if mentioned, is by spotting the test reagents in the reaction area and drying the test card. During manufacture, each card would be handled individually. For example, U.S. Pat. No. 4,668,472 generally describes manufacturing by forming cups or wells into which the reagents are dispensed. The forming, filling and drying operations can be performed on the same machine, with wells of the reagent prepared and cut out for assembly. Although this may streamline the manufacture, it limits the flexibility of manufacturing and leads to variability, that is, nonuniform reaction surface preparation.
U.S Pat. No. 4,565,783 describes a device for culturing and observing microorganisms which may also be used for microbiological tests using antibiotics. A substrate is coated with an adhesive and a water soluble powder, which includes a nutrient or gel, which is adhered to the adhesive. A coversheet protects the culture and microorganism from contamination during incubation and growth. The device also includes an opening with limits for retaining fluid. This device is useful where incubation is required and where liquids are added. The device requires a cover sheet to isolate the contents from the environment, prevent evaporation and to prevent contact by the user during incubation and handling. Thus the prior art has provided test cards and slides for culturing microorganisms and for wet specimen analysis.
An objective of the present invention is to provide a test slide for performing simple microbiology diagnostic tests; which is in a new and useful format; which is constructed so as to not require assembly after the analysis is initiated; which has a test reagent carried on the slide in a dry format, ready for use; wherein the test reagent is conveniently included in a dry carrier without the need for adhesive; which can be readily handled; and which is also more economical and easier to manufacture than prior art slides and cards.
It is also an objective of the invention to provide for a process that allows automated or semi-automated assembly of the test slides which is labor saving, which is economical, and which eliminates variability of reactions by preparing the reaction surface in a uniform manner.
In accordance with the invention, the test slide comprises a plastic substrate strip or chip, which is transparent and dimensionally stable, and has a diagnostic reagent coating on an area thereon, and a mount constructed and arranged to form a border around and behind the substrate chip. The mount has rigid back and front walls or sides with inner surfaces which have a layer of self-adhesive adhesive and the substrate strip is positioned between the walls of said mount. The adhesive layers are -bound to one another by the adhesive to secure the substrate in the mount and to keep the mount assembled. The mount has at least one opening in the front wall overlying the diagnostic reagent area on the strip, providing access to a coating on the strip which includes a diagnostic reagent. The back wall is opaque to provide contrast for the transparent substrate.